Combining induced mutation and protoplasting for strain improvement of Aspergillus oryzae for kojic acid production.

By combining induced mutation, using NTG and UV irradiation, and protoplasting of a wild type strain of Aspergillus oryzae ATCC 22788, a hyper-producing strain was obtained that accumulated 41 g kojic acid l(-1) in shake-flasks, which was 100-fold higher than that in the wild type strains. Similar production of kojic acid was obtained in 5 l stirred-tank fermentations.

Fusion protein of the hyaluronan binding domain from human TSG-6 with luciferase for assay of hyaluronan.

The gene expression plasmid, pET-Lmluc, for the fusion protein of the hyaluronan binding domain from human TSG-6 [product of tumor necrosis factor (TNF)-stimulated gene-6] and luciferase from Renilla reniformis was constructed. The fused gene was expressed in Escherichia coli and the resulted insoluble Lm-luc fusion protein was purified and refolded to recover both the hyaluronan binding capability and the luciferase activity. Hyaluronan as low as 1 ng ml(-1) was detected by using the indirect enzymatic immunological assay with the refolded Lm-luc fusion protein.